Yesterday's engagement between a US Navy F/A-18E Super Hornet and an Syrian Su-22 Fitter attack jet has sent the already stalling US-Russian relationship into a nose dive. As we expected, Moscow's response to the incident has been intense and the likelihood that other encounters in the air and on the ground turn deadly between US backed coalition and pro-Assad forces has only increased.

A swirl of Russian statements on the event hit news wires this morning, with Moscow making it clear that any coalition aircraft flying east of the Euphrates river will be closely watched and targeted by Russian forces, with the Russian MoD stating:

“In the areas of combat missions of Russian air fleet in Syrian skies, any airborne objects, including aircraft and unmanned vehicles of the [US-led] international coalition, located to the west of the Euphrates River, will be tracked by Russian ground and air defense forces as air targets.”

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Syrian Su-22 Fitter pilot at Shayrat Air Base the day after the US struck it with 59 Tomahawks.

The Russian MoD has also said that it is halting even the lowly cooperation it had with the US. This was being facilitated by the Memorandum on Prevention of Incidents and Ensuring Air Safety In Syria agreement that led to the creation of a sometimes effective but ultimately necessary hotline between Russian commanders in western Syria and US-led coalition commanders in Qatar. This so called "deconfliction phone" allowed either side to hale the other during emergencies—like when one force is attacking the other seemingly by accident—and to smooth over potential operational hurdles before or after significant issues arise.

Russia claims the phone was never used before the Super Hornet fired on the Su-22, stating:

"The command of the coalition forces did not use the existing communication channel between the air commands of Al Udeid Airbase and the Khmeimim Airbase to prevent incidents in Syrian airspace."

The US has a different account, stating that it did indeed attempt to use the deconfliction channel before clearing the Super Hornet to fire. Now, as part of Russia's response to Sunday's air-to-air engagement, Russia says they are no longer going to answer the deconfliction phone if it rings:

"As of June 19 this year, the Defense Ministry of the Russian Federation has ended its interaction with the US side under a memorandum for preventing incidents and providing for safe flights during operations in Syria and demands that the US command carry out a careful investigation and report about its results and the measures taken."

After the U.S. cruise missile attack on Syria's Shayrat air base in April, Moscow said they were shuttering the hotline operation, but it came back into existence some time after. It is not clear if they will stick to their word this time, although their intent to stop the patchy cooperation is being more clearly stated this time than last.

ALBERTO PIZZOLI/AFP/Getty Images

AIM-120 AMRAAMs being rolled on the flight-deck for loading aboard US Navy fighter aircraft operating over Syria.

Still, the Kremlin is viewing the shoot-down, at least publicly, as an act of blatant aggression by the US and its coalition partners and is demanding a full investigation into to incident, including why the deconfliction phone was not used first before the order was given to blow the Su-22 out of the sky. And the rhetoric doesn't stop there, Deputy Foreign Minister Sergei Ryabkov said that the downing of the Su-22 was like "helping the terrorists that the U.S. is fighting against," and added "what is this, if not an act of aggression?" The official MoD statement on the incident also has some harsh words, stating in part:

"Syrian air force aircraft destroying American Aviation in Syrian airspace, cynical violation of the sovereignty of the Syrian Arab Republic. Repeated Hostilities Aviation USA under the guise of "fighting terrorism" against the legitimate armed forces United Nations Member States, are a flagrant violation of international law and in fact military aggression towards the Syrian Arab Republic."

Although the exact parameters of the engagement remain unclear, CBS reports that two missiles were fired from the rear-aspect of the Su-22, with one missing the aircraft and the other detonating at its rear, blowing off the jet's tail and sending it into the ground. Neither Russia nor the US has put out any information as to the fate of the Su-22's pilot, although some sources with contacts in Syria say he has been captured alive.

As for the U.S. response to Russia's tough talk, the Pentagon is drawing a hardline with Captain Jeff Davis stating:

"We do not seek conflict with any party in Syria other than ISIS, but we will not hesitate to defend ourselves or our partners if threatened."

"I'm confident that we are still communicating between our operations center and the Russia federation operations center and I'm also confident that our forces have the capability to take care of themselves."

But the reality of the situation is likely far more complicated. There is talk that Russia will begin patrolling east with its best fighter aircraft in the region, and that the way the coalition does business has also had to adapt significantly in recent hours. This has included repositioning aircraft and bolstering defensive air capabilities over the country. Lieutenant Colonel Damien Pickart said the following while speaking for Central Command (CENTCOM):

"As a result of recent encounters involving pro-Syrian Regime and Russian forces, we have taken prudent measures to re-position aircraft over Syria so as to continue targeting ISIS forces while ensuring the safety of our aircrew given known threats in the battlespace."

All this makes it harder for the coalition to go after ISIS with the resources available, and has occurred at a critical time in the coalition's campaign to rout ISIS from the region. The final assault on the Islamic State's capital of Al Raqqa just began officially last week, and air power is critical in leveraging the most dramatic impact that American special operators on the ground fighting alongside indigenous rebel forces can provide.

ALBERTO PIZZOLI/AFP/Getty Images

Super Hornets roar off the deck. Closest aircraft is configured in the "Five Wet" tanker configuration.

The biggest risk is to US aircraft operating near pro-Assad forces operating in Syria's central and southern regions, and especially to US drones that may venture west into airspace that is defended by some of Russia's most capable air defense systems not to mention a small contingent of Russian fighters based near Latakia. Traditionally, these have been Su-35s.

Russia could begin flying air patrols out into eastern Syria as a challenge to coalition forces, but that level of recklessness may be a step too far for the Kremlin considering that it is already deeply involved in the conflict. If the jet that the US Navy shot down had been Russian things would be different. But even then, after a Russian Su-24 was shot down by Turkey a year and a half ago, killing one of its aircrew, tensions drastically increased between the two countries, but the bad blood was fairly short-lived in retrospect.

If Russia tests the US and its coalition, more assets will likely be needed to fight the air war over Syria, and a deeper deployment of F-22s—an aerial weapon system Russia cannot compete with over Syrian territory and that can act as a deconfliction referee of sorts—is possible if not probable. Even the deployment of F-15Cs to provide dedicated defensive counter-air support for strike and support aircraft operating over eastern Syria would take the burden off multi-role fighters that are already heavily tasked fighting the anti-ISIS campaigns over Iraq and Syria. The presence of these aircraft over coalition-controlled Syrian territory would also act as a deterrent of sorts to any Syrian or Russian aircraft that seek to meddle in coalition operations

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Armed-up Su-35S stationed at Russia's airbase south of Latakia Syria. The Su-35S is Russia's most capable operation fighter.

Maybe one last thing to consider is that this shoot-down, and the mess that has followed, could have been avoided if the US neutered Assad's air power in full instead of executing a token cruise missile attack on Shayrat air base alone last April. That attack was largely ineffective and counterproductive, and didn't even put the base—one of the SyAF's primary Su-22 operating installations—out of commission once and for all. In fact, it didn't even destroy all the aircraft based there. Su-22s were flying sorties from the installation's intact runway just hours after the much-touted strikes occurred.

Assad still has his air force doing his bidding, and now that same air force is under the protective umbrella of the Russian military. So now if you want to take out Assad's aerial war fighting capabilities, you have to attack Russia in the process.

With this in mind, don't expect Assad's air force to stop being a menace anytime soon.